What was found
AIRCRAFT WAS GROUNDED: TRIED TO ENGAGE AUTOPILOT B AT 16,000, TRIED TO ENGAGE AUTOPILOT A, NEITHER WOULD ENGAGE. I RESET THE ENTIRE MODE CONTROL PANEL, TURNED OFF AUTO THRUST, BOTH FLIGHT, VNAV, LNAV, REENGAGED -AUTOPILOTS STILL WOULD NOT ENGAGE. FOUND FAULT CODE 22-11822 FLIGHT CONTROL COMPUTER DATA INVALID. REPLACED FLIGHT CONTROL COMPUTER 1 PER AMM 22-11-33.